Technologies for recognizing a denomination, an authenticity, and a fitness of a paper sheet such as a banknote that is a valuable security, are well known in the art. One such technology (for example, Patent Document 1) is explained below as an example. A deposit money recognition unit performs recognition of the denomination, fitness, and authenticity of deposited banknotes and detects whether there occurs any transport error. The banknotes that have been determined to be fit notes and unfit notes are stored in a safe based on the denomination. The number of fit notes and unfit notes in each denomination, and their ratios are acquired and stored as fitness information. Upon request of a withdrawal transaction, the banknotes are fed out from the safe as per the requirement, a fitness recognition is performed by a dispensing money recognition unit, the notes that are determined to be fit notes are dispensed, and the notes that are determined to be unfit notes are stored in a dispensing reject bin.
In view of increase of counterfeit paper sheets such as banknotes in recent years, the banknotes are provided with, as a preventive measure against counterfeit forgery, security information in the form of including magnetic characteristics or a magnetic thread in the banknote, printing the banknote in a fluorescent ink, or embedding a hologram onto the banknote. Availability of sophisticated copying machines and scanners has enabled forgery of counterfeit paper sheets. Technological development is ongoing to counter this kind of fraud.